Worlframalpha.com Facebook Report

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1 Worlframalpha.com Facebook Report

2 For Tuesday: have read up through chapter 2 Next week will start chapter 3 New lab today: Simple Programs

3 Integer division? o 1//3 o - 1//3 Range start at something other than 0? range([start,] stop [,step])

4 for i in range(5): print (i*i) for i in [3, 1, 4, 1, 5]: print (i, end= ) for i in range(4): print ( Hello ) for i in range(5): print (i, 2**i)

5 Print out 1, 2, 3, 4 Using a for loop, each on a different line Using a for loop, on the same line Now, print out the reverse sequence by changing only the print statement (not the for statement)

6 Summing sum=0 for i in range(5): sum = sum + i print (sum)

7 Psudocode More precise than English Not a programming language Good for thinking Program to convert C to F? F (9/5)C + 32

8 The So`ware Development Process Analyze the Problem Determine Specificaeon Create a Design Implement Design Test/Debug the Program Maintain Program Python Programming, 2/e 8

9 Example Program: Temperature Converter Problem: US student needs to know temperature in F Python Programming, 2/e 9

10 Example Program: Temperature Converter Analysis temperature is given in Celsius user wants it in degrees Fahrenheit Specificaeon Input temperature in Celsius Output temperature in Fahrenheit Output = 9/5(input) + 32 Python Programming, 2/e 10

11 Example Program: Temperature Converter Design Input, Process, Output (IPO) Prompt the user for input (Celsius temperature) Process it: convert to Fahrenheit. F = 9/5(C) + 32 Output the result to screen Python Programming, 2/e 11

12 Example Program: Temperature Converter Before coding write a rough dra` program Psudocode More precise than English Not a programming language Good for thinking Python Programming, 2/e 12

13 Example Program: Temperature Converter Pseudocode: Input temperature in degrees Celsius (call it celsius) Calculate fahrenheit as (9/5)*celsius+32 Output fahrenheit Next, convert to Python Python Programming, 2/e 13

14 Example Program: Temperature Converter #convert.py # A program to convert Celsius temps to Fahrenheit # by: Susan Computewell def main(): celsius = eval(input("what is the Celsius temperature? ")) fahrenheit = (9/5) * celsius + 32 print("the temperature is ",fahrenheit," degrees Fahrenheit.") main() Python Programming, 2/e 14

15 Example Program: Temperature Converter Once we write a program, we should test it! >>> What is the Celsius temperature? 0 The temperature is 32.0 degrees Fahrenheit. >>> main() What is the Celsius temperature? 100 The temperature is degrees Fahrenheit. >>> main() What is the Celsius temperature? - 40 The temperature is degrees Fahrenheit. >>> Python Programming, 2/e 15

16 Industrial- strength teseng hmp://trenchescomic.com/tales/post/advancement- lies Maintenance Documentaeon Knowledge transfer

17 Google Glass hmp:// v=9c6w4ccu9m4 hmp://

18 Example Program: Future Value Problem: Our student wants to invest money in a savings account but doesn t know how much he ll make over 10 years. Python Programming, 2/e 18

19 The So`ware Development Process Analyze the Problem Determine Specifica6on Create a Design Implement Design Test/Debug the Program Maintain Program Python Programming, 2/e 19

20 Example Program: Future Value Analysis Money deposited in a bank account earns interest How much will account be worth in 10 years? Inputs: principal, interest rate Output: value of the investment in 10 years Assumpeons? Python Programming, 2/e 20

21 Example Program: Future Value Specificaeon User enters inieal amount to invest (the principal) User enters annual percentage rate (the interest) Python Programming, 2/e 21

22 Example Program: Future Value Program Future Value Inputs principal: amount of money being invested, in dollars apr: annual percentage rate expressed as decimal number Output Total value of the investment 10 years in the future Process Value a`er one year is given by principal * (1 + apr) This needs to be done 10 emes. Python Programming, 2/e 22

23 Example Program: Future Value Design Print an introduceon Input the amount of the principal (principal) Input the annual percentage rate (apr) Repeat 10 emes: principal = principal * (1 + apr) Output the value of principal Python Programming, 2/e 23

24 Example Program: Future Value Implementaeon Each line translates to one line of Python (in this case) Print an introduceon print ("This program calculates the future") print ("value of a 10- year investment.") Input the amount of the principal principal = eval(input("enter the ini6al principal: ")) Python Programming, 2/e 24

25 Example Program: Future Value Input the annual percentage rate apr = eval(input("enter the annual interest rate: ")) Repeat 10 emes: for i in range(10): Calculate principal = principal * (1 + apr) principal = principal * (1 + apr) Output value of the principal at end of 10 years print ("The value in 10 years is:", principal) Python Programming, 2/e 25

26 Example Program: Future Value # futval.py # A program to compute the value of an investment # carried 10 years into the future def main(): print("this program calculates the future value of a 10- year investment.") principal = eval(input("enter the inieal principal: ")) apr = eval(input("enter the annual interest rate: ")) for i in range(10): principal = principal * (1 + apr) print ("The value in 10 years is:", principal) main() Python Programming, 2/e 26

27 Example Program: Future Value >>> main() This program calculates the future value of a 10- year investment. Enter the inieal principal: 100 Enter the annual interest rate:.03 The value in 10 years is: >>> main() This program calculates the future value of a 10- year investment. Enter the inieal principal: 100 Enter the annual interest rate:.10 The value in 10 years is: Python Programming, 2/e 27

28 Example Program: Distance Averager Problem: Our poor study- abroad student in Europe needs to know the average distance between three ciees, in miles. 1 Kilometer = 0.62 Mile Python Programming, 2/e 28